The “true genius of America,” Barack Obama said the night the country elected its first black president in 2008, is “that America can change.”

The uproar over the George Zimmerman verdict is a vivid, somber reminder of how that change comes slowly, even haltingly at times, and how much race still courses through American politics.

While the days of legal segregation and institutional discrimination are now a generations-old memory, major policy disputes roiling Washington continue to have racial subtexts. The immigration fight is in one sense a fight for the loyalty of the growing, influential Latino voting bloc. The battle over how or whether to strengthen the recently diluted Voting Rights Act stirs fears that blacks in the South will lose long-cherished rights. Other clashes over the size, scope and cost of government continue to have racial undercurrents as well.

“Different groups have different views of what government policy should be, and that doesn’t seem to be going away at all,” said Merle Black, a Southern politics expert at Emory University in Atlanta.

The Zimmerman verdict has the potential to harden racial attitudes that have been developing for generations. The Sanford, Fla., neighborhood watch volunteer was found not guilty Saturday in connection with the death of black teenager Trayvon Martin.

History shows that once certain groups of voters learn to trust a political party, they don’t switch allegiances. They remember perceptions of who worked against their interest, perhaps in opposing civil rights laws or denying funding to programs for lower-income people.

Black voters were intensely loyal to the Republican Party for roughly 70 years, remembering Abraham Lincoln’s abolishing slavery and the party stalwarts who continued that legacy. Democrats were the party of the segregated South.

The perception began to change during Franklin Roosevelt’s presidency, as his New Deal helped ease the Depression’s pain and first lady Eleanor Roosevelt became a champion of civil rights. When her husband ran for re-election in 1936, he got an estimated 71 percent of the black vote. Obama, the nation’s first black president, got 93 percent of the black vote in 2012.

The Latino community is still emerging as a political force. Though it’s been trending more Democratic in recent years, Republicans still see opportunities. Polls suggest Latino voters will back Republicans who demonstrate sensitivity to immigration issues.

Sen. Marco Rubio, R-Fla., has been a leader in the bipartisan effort to create a path to citizenship for the country’s 11 million undocumented immigrants. He’s endured withering conservative criticism for his stance and yet remains a prominent voice in his party and a potentially formidable 2016 presidential contender.

“Clearly there’s a subtext to this whole fight over immigration. Both parties have blatant political motives on this issue,” said Peter Brown, assistant director of the Quinnipiac poll and author of “Minority Party,” a book about race in politics.

The Latino community is watching closely. An America’s Voice/Latino Decisions poll of Hispanic voters last month found 53 percent named immigration as the nation’s most important issue. Nearly two-thirds said they knew an undocumented immigrant.

They also showed a willingness to vote for either party, as 48 percent said they had voted for a Republican in the past. As the undocumented immigrants become legal voters, most could very well side with either party, argued Adrian Pantoja, senior analyst at Latino Decisions, which studies Hispanic voting trends.

“Undocumented immigrants are still learning the positions and orientations of the political parties,” he said.

But the more the Democratic Party promotes itself as the party of racial sensitivity, the more it hamstrings Republicans’ efforts to diversify. Obama on Sunday issued a somber statement asking “every American to respect the call for calm reflection from two parents who lost their young son.” Sixteen months ago, Obama was more blunt. “When I think about this boy I think about my own kids,” he lamented.

Republicans this week have said little. Neither House Speaker John Boehner, R-Ohio, or Senate Republican leader Mitch McConnell of Kentucky has spoken publicly about the case.

Republican Party officials routinely deny any racial undercurrent to their thinking on immigration, voting rights or for that matter any other issue. The party earlier this year launched an aggressive effort to woo minority voters through grassroots organizing and other strategies.

But long-held images persist, and there has been little Republican enthusiasm for revisiting last month’s Supreme Court ruling on the 1965 Voting Rights Act. The court struck down a key provision requiring areas with histories of racial bias to get federal approval for changes in voting laws. The act is a touchstone for many blacks, who recall its pivotal role in securing the right to vote.

Republicans urge looking at a broader picture. Wooing minorities will not happen all at once, and a key way to engage them, said former Ohio Secretary of State Ken Blackwell, is to stress the party’s economic views.

“As increasing numbers of people grow tired of politics that divide people,” he said, “you try breaking down the barriers with a growing economy.”

His party has had only limited success with that mantra. President George W. Bush got 44 percent of the Latino vote in 2004. The former Texas governor’s record as sensitive to Latino concerns such as education and immigration helped, but so did the booming economy.

Overall, though, minority voters still zero in on certain issues more than whites. A 2009 Pew study of black voter attitudes found 53 percent of blacks thought major conflict existed between blacks and whites, while only one-third of whites felt that way.

Now comes the Zimmerman case, sparking a new dialogue about race in American life.

It’s likely to continue for some time, said Black of Emory University, because "in different ways, race and ethnicity still structures a lot of American politics."